The following paper discusses the application of two subdivision algorithms for the purpose of finding an optimal way of rendering smooth spherical surfaces. Subdivision algorithms are used on three dimensional models. These algorithms typically manipulate the original object to produce one that is more visually pleasing and more realistic to the object we are attempting to recreate. We applied two popular subdivision algorithms to some simple meshes to compare their outcomes. In this project we implemented some of these algorithms in order to gain some insight into how these algorithms differ in the way that they are transforming the input mesh. Our desired goal was to see if there is any basis for which we can say that one algorithm outperforms the other. Our comparison runs through several iterations of subdivision and compares their theses meshes visually. In comparing these meshes our desired visual outcome is a mesh that is more smooth or more spherical. Another metric we looked at was the number of faces being produced for each mesh. In addition, we compared the algorithms in terms of the time they took to perform subdivision. These metrics form the basis for our comparison of performance and we discuss the details of these further in this paper.In our results we found that the two algorithms we are comparing perform quite similarly on certain meshes with respect to the visual output and the time they take to perform subdivision. On meshes of different types however the algorithms might output visually distinguishable meshes upon repeated subdivisions. Finding what factors influence whether the algorithms perform similarly provides an avenue for future work.

Polioviruses have been around for a long time in man's history. Before the development of killed and live virus vaccines in the 1960's, poliomyelitis was a serious problem in public health. Since then paralytic poliomyelitis remains a threat in certain underdeveloped countries but has been considered a conquered disease in the developed world. The molecular epidemiology of wild-type 1 polioviruses (WPV1) isolated in Angola in 2005, the Democratic Republic of the Congo (DRC) in 2006-2008 and Namibia in 2006 were investigated by sequence analysis of the complete VP1 gene of all isolates. All outbreak viruses clustered with the Indian type 1 genotype (SOAS) which was unique to India circulating endemically in the Uttar Pradesh (UP) and Bihar provinces in Northern India. Epidemiological and virological analyses suggested that the Namibia outbreak virus had been circulating without detection for at least one year in Angola. Four cases of acute flaccid paralysis (AFP) occurred in children in Madagascar in 2005. Molecular analysis confirmed cVDPV type 2 and 3 in affected patients. The first case, occurred in Toliara II district, on 09 April 2005. The last two cases were in the Toliara I and Beloha districts and paralysis onset on 26 June and 13 July 2005 respectively. Partial genomic sequencing of the poliovirus isolates revealed considerable divergence from the prototype Sabin strain in all cases. This is the second time that type 2 cVDPV is associated with an outbreak of AFP in Madagascar, and to our knowledge the first time that a type 3 cVDPV is identified in Madagascar. A total of fifty-six children with AFP were found to excrete VDPVs of serotype 2 in the DRC between 2005 and 2010. These viruses represent at least three emergences and at least two outbreaks. Partial genomic sequencing of the poliovirus isolates revealed considerable nucleotide sequence divergence of between 1.1% to 2o/o from the prototype Sabin strain in the VP1 region of the viral genome. This was the first time that a type 2 cVDPV outbreak was detected in the DRC. In total, 89 viral isolates obtained from Ethiopia during 2007 to 2010 and partial sequencing analysis confirmed that 13 isolates were VDPV's. Seven AFP cases were type 3, 4 AFP cases were type 2 and 2 contacts for type 3. Partial genomic sequencing of the poliovirus isolates revealed considerable divergence from the prototype Sabin strain in all cases. Finally, cases of AFP where only Sabin-like viruses were identified were investigated in South Africa with 11 possible VAPP cases identified with recombinant events in the 30 region and also revealing a mutation that restore the original stem-loop structure in the internal ribosomal entry site (IRES) in the 5' Non-Translated Region (NTR). In this study, the molecular epidemiology of poliovirus outbreaks that occurred in Angola, Namibia, and the DRC is described that were associated with wild polio 1 and 3. Investigation of Sabin-like vaccine strains in the DRC, Madagascar and Ethiopia identified vaccine-derived polioviruses in AFP cases as well as possible vaccineassociated paralytic poliovirus in South Africa. Copyright / Thesis (PhD)--University of Pretoria, 2012. / Medical Virology / Unrestricted

In den 1950er-Jahren stellte das epidemische Auftreten der spinalen Kinderlähmung (Poliomyelitis) die Gesundheitssysteme weltweit vor große Herausforderungen. Da eine kausale Therapie der Viruserkrankung nicht existierte, kam der Expositionsprophylaxe eine besondere Bedeutung zu. Letztlich gelang es erst durch die Entwicklung von Impfstoffen, die spinale Kinderlähmung nachhaltig zurückzudrängen. In der Deutschen Demokratischen Republik (DDR) wurde 1960 erstmals in Deutschland die Schluckimpfung nach Sabin-Tschumakow verabreicht, mit der binnen eines Jahres die nahezu vollständige Eradikation der spinalen Kinderlähmung in der DDR gelang. Der Artikel zeichnet anhand von unveröffentlichtem Archivmaterial die systematisch angelegte Impfaktion am Beispiel der damaligen Bezirkshauptstadt Halle (Saale) nach. Allein dort wurden im Mai 1960 innerhalb von 3 Tagen 63.328 Kinder und Jugendliche immunisiert. Bei 78.085 im Vorfeld erfassten Impflingen entsprach dies einer Quote innerhalb der poliovulnerablen Bevölkerungsgruppe von rund 81 %. Die Quellen zeigen, dass die staatliche Struktur des Gesundheitswesens der DDR und das Prinzip der aufsuchenden Impfung zum Erfolg der Impfaktion beitrugen. / In the 1950s, the epidemic occurrence of infantile paralysis (poliomyelitis) posed major challenges to health systems worldwide. Since there was no causal therapy for the viral disease, exposure prophylaxis was of particular importance. Ultimately, it was only through the development of vaccines that infantile paralysis could be permanently reduced. In 1960, the Sabin–Tschumakow oral vaccine was administered in the former German Democratic Republic GDR for the first time in Germany. Within one year, this vaccine succeeded in almost completely eradicating polio in the GDR. The article uses unpublished archival material to trace the systematic vaccination campaign using the example of the then district capital Halle (Saale). There alone, 63,328 children and adolescents were immunized within three days in May 1960. With 78,085 vaccinees recorded in advance, this corresponded to a rate within the polio-vulnerable population group of around 81%. The sources show that the GDR’s government healthcare system and the principle of outreach vaccination contributed to the success of the vaccination campaign.

This thesis presents a new technique for the reconstruction of a smooth surface from a set of 3D data points. The reconstructed surface is represented by an everywhere -continuous subdivision surface which interpolates all the given data points. And the topological structure of the reconstructed surface is exactly the same as that of the data points. The new technique consists of two major steps. First, use an efficient surface reconstruction method to produce a polyhedral approximation to the given data points. Second, construct a Doo-Sabin subdivision surface that smoothly passes through all the data points in the given data set. A new technique is presented for the second step in this thesis. The new technique iteratively modifies the vertices of the polyhedral approximation 1CM until a new control meshM, whose Doo-Sabin subdivision surface interpolatesM, is reached. It is proved that, for any mesh M with any size and any topology, the iterative process is always convergent with Doo-Sabin subdivision scheme. The new technique has the advantages of both a local method and a global method, and the surface reconstruction process can reproduce special features such as edges and corners faithfully.

Made available in DSpace on 2014-08-26T17:15:07Z (GMT). No. of bitstreams: 2 license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) 106.pdf: 11011427 bytes, checksum: 47de23ce5361c89a3fe418a1ea675e43 (MD5) Previous issue date: 2006 / Fundação Oswaldo Cruz. Instituto Nacional de Controle de Qualidade em Saúde / Cinco cepas P1/Sabin, 20 cepas P2/Sabin e 2 cepas P3/Sabin isolados a partir de amostras do meio ambiente no Brasil foram analisadas. Neste estudo todos os isolados foram caracterizadas pelo seqüenciamento parcial da região 5 não codificante (NCR) e pelo seqüenciamento completo do gene da proteína VP1, com o objetivo de demonstrar mutações, as quais são importantes para a reversão à neurovirulência. O seqüenciamento parcial da região 5'NCR revelou que todos os poliovírus isolados do sorotipo 1 apresentaram populações de revertentes G480 ->A e os 2 isolados do sorotipo 3 apresentaram a reversão U472 ->C. Nenhum isolado do sorotipo 2 apresentou mutação A481 ->G. O completo seqüenciamento da região de VP1 demonstrou que nenhum isolado P1/Sabin apresentou substituição nucleotídica, as 2 cepas P3/Sabin apresentaram VP1-6 (Thr ->Iso) e 16 cepas P2/Sabin apresentaram VP1-109 (Lys ->Arg). O isolado P2/26183 também apresentou mutações VP1-103 (Ser ->Lys) e VP1-116 (Val ->Gly), enquanto P2/26184 apresentou VP1-155 (Cys ->Tyr). As regiões 2C e 3D do genoma foram investigadas pelo uso de primers que hibridizam nestas áreas com o objetivo de verificar a presença de recombinação. Nenhuma cepa envolvida no estudo foi identificada como recombinante. Nenhum poliovírus derivado da vacina foi detectado. / Five strains of P1/Sabin, 20 strains of P2/Sabin and 2 strains of P3/Sabin isolated from environmental samples in Brazil were analyzed. In this study all isolates were characterized by partial genomic sequencing of the 5’ noncoding region (NCR) and the complete VP1 protein gene VP1, with the objective of finding mutations, which are important for neurovirulence reversion. Partial sequencing of 5’NCR revealed that all type 1 poliovirus isolates had the G→A substitution at the nt 480 and the 2 type 3 poliovirus isolates had the U→C substitution at the nt 472. None type 2 isolate had A→G substitution 481. The complete sequencing of the VP1 region showed that none P1/Sabin strain had nucleotide substitution, the 2 P3/Sabin strain had VP1"6 (Thr→Iso) and 16 P2/Sabin strain had VP1"109 (Lys→Arg). The isolate P2/26183 also presented mutations VP1"103 (Ser→Lys) and VP1"116 (Val→Gly), while P2/26184 showed VP1"155 (Cys→Tyr). The 2C and 3D regions of the viral genome were investigated by the use of primers that hybridize in these areas with the objective to verify the presence of recombination. None of the strain involved in this study was identified as recombinant. None vaccine derived poliovirus was detected.

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